Honeywell International Inc.
I/O MESH ARCHITECTURE FOR A SAFETY INSTRUMENTED SYSTEM

Abstract:

A safety instrumented system (SIS) includes safety controllers, and safety input/output (I/O) modules coupled to safety field devices that are coupled in parallel with a process control system's field devices to processing equipment which is configured and controlled to run a process. An I/O mesh network between the safety controllers and the safety I/O modules is configured for selecting any safety controller to become coupled to any safety I/O module to function as a pool of safety I/O modules so that any safety controller is configurable to receive sensor signals from and transmit control signals to any safety field device. The safety field devices are for monitoring process variable(s) for the process so that when one of the safety controllers recognizes a hazardous condition regarding the processing equipment, the SIS independently takes action to keep the processing equipment under control or bring it to a safe state.